Traditional fire-fighting methods for fighting fires in storage vessels containing flammable liquids may require the application of a plurality of fire-fighting agents issued from one or more discharging apparatuses. These methods include:                a) Long range fire-fighting methods including fixed, semi-portable or portable systems that discharge fire-fighting agents from a position located afar from the storage vessel. These include fixed monitors, semi-portable monitors, fixed cannons, vehicle mounted cannons, hand held nozzles, etc.        b) Fixed systems permanently installed on the storage vessel. These include fixed foam chambers mounted on the roof of the storage vessel, circumferential discharge system or seal area protection systems on floating roof tanks, sub-surface injection systems, etc.        c) Portable systems that are used for mounting discharging apparatuses on the storage vessel.Each of these traditional fire-fighting methods possess certain limitations that can include one or more of the following:        
their effectiveness in the application of the fire-fighting agent;
the operating system requirements;
the costs associated with the acquisition of the fire-fighting equipment and necessary peripheral equipment;
the costs associated with the operation of the equipment, namely the volume of fire-fighting agent consumed;
the time required to extinguish the fire and resume normal operations; and
the associated damages related to property, plant, equipment and lost production.
The limitations of long range fire-fighting methods discussed in a) above, include the following:                a significantly higher minimum system pressure is required for the fire-fighting agent to reach the surface of the flammable liquid in the storage vessel;        the costs are significantly higher in acquiring, maintaining and operating fire-fighting equipment operating at these higher pressures;        the radial component in the stream velocity is allowed more time to develop, hence dispersing the fluid flow, thereby increasing the cross-sectional impact area of the fire-fighting agent, thus decreasing the concentration of the fire-fighting agent, and finally reducing the effectiveness of the fire-fighting agent in arresting the fire;        the atmospheric winds surrounding the vessel and the convective gases arising from the fire also contribute significantly to the dispersion of the fire-fighting agent thereby reducing the effectiveness of the fire-fighting agent in arresting the fire; and        the longer trajectory of the stream of the fire-fighting agent from the discharge point to the target area increases the amount of air dragged into the stream of the fire-fighting agent and onto the surface of the flammable liquid thereby increasing the oxygenation of the fire.The Industry has generally sought to address the above performance limitations in arresting the fire by increasing the rate of application of fire-fighting agents from 3,000 GPM to 5,000 GPM to 10,000 GPM, using a “surround and drown” approach. This method significantly increases the amounts of fire-fighting agents consumed and thereby the costs associated with extinguishing the fire.        
The limitations of fixed systems that are permanently installed on storage vessels, discussed in b) above, include the following:                the foam chambers permanently installed on the roof of storage vessels, traditionally the first line of defense in the event of a fire, are highly vulnerable and are frequently rendered entirely inoperable in the initial phase of the conflagration when violent explosions may occur; and        the Sub-surface injection systems can be rendered inoperable due to the effects of an explosion and more often due to clogging of the system.        
The limitations of portable systems that are used for mounting discharging apparatuses on the storage vessel, discussed in c) above, can include one or more of the following:                they operate only with pre-mixtures of foam concentrate and water;        they do not include apparatus for mixing the fire-fighting agents with a conveying media;        they are designed to discharge only one type of fire-fighting agent, for example foam;        the foam discharge device is not detachable from the installation apparatus and therefore the installation of each discharge device requires its own installation apparatus; and        they do not include an apparatus for the transportation of the entire system.        
In view of the limitations of the traditional fire-fighting methods discussed above, the applicants have developed a portable system for extinguishing fires in storage vessels containing flammable liquids that seeks to complement the positive performance aspects of these methods while addressing many of their core performance limitations.
There is therefore a need in the art for low-cost fire-fighting equipment that can be used to extinguish fires on or within a flammable substance in storage vessel. There is also a need for a system that is not permanently installed on the storage vessel so that the fire-fighting equipment is not damaged or destroyed by the explosions or conflagrations often associated with the initial stage of a fire. There is also a need for a portable fire-fighting apparatus that does not attempt to spray fire-fighting agents from a remote position. In addition, there is a need for a fire-fighting apparatus that does not utilize costly high-pressure equipment.